Snail colour frequencies

Snail colours divided into colour classes (white, banded, red and others) for two subsamples per skerry and visit. Data covers 4 populations to which only white snails were introduced June 1992, 3 populations to which only banded snails were introduced and one population to which only red snails were introduced.本数据集针对每座礁岛及每一次采样设置两组子样本，将蜗牛体色划分为白色、带纹、红色及其他四类颜色类别。数据集共涵盖8个蜗牛种群：其中4个种群于1992年6月仅引入白色蜗牛，3个种群仅引入带纹蜗牛，剩余1个种群仅引入红色蜗牛。